How to administer semaglutide injections safely and correctly

What do you need to prepare before you inject?

Good preparation makes the injection itself easy. Take the Wegovy pen out of the fridge about 15 to 30 minutes before you plan to use it; injecting cold liquid can sting more than it needs to. While the pen is coming to room temperature, wash your hands thoroughly with soap and water.

You will need a clean alcohol swab to clean the injection site. Our alcohol swabs are sized for this purpose if you need a reliable supply. Wipe the chosen area and let it air-dry fully, injecting through wet skin can cause brief stinging.

Check the pen window. The liquid should be clear and colourless; if it looks cloudy, discoloured, or contains particles, do not use it and contact your prescriber. Remove the pen cap but do not pull off the needle cover until you are ready to inject. The Wegovy pen comes with a needle already attached, so no separate needle change is required for each weekly dose, the needle is integrated into the pen cap design. Keep the used pen well out of reach of children.

If you want more detail on the full semaglutide injection process beyond the technique itself, the guide to taking semaglutide injections covers timing, schedule and what to expect week by week.

Which injection sites work best for administering a semaglutide pen?

The three licensed sites for subcutaneous injection are the abdomen (belly), the front of the thigh, and the upper outer arm. All three work well; the choice usually comes down to what is easiest to reach and pinch.

For the abdomen, aim for the area around the navel but stay at least 5 cm away from the navel itself and from any scars. The thigh site works particularly well if you are injecting at home alone, since you can see what you are doing clearly. The upper arm is convenient but can be harder to reach without help.

Rotation is important. Returning to exactly the same spot week after week can cause small lumps of hardened tissue under the skin (a condition called lipohypertrophy) which slows down how reliably the medicine is absorbed. A simple approach is to divide each site into quarters and move one quarter clockwise each week, returning to the start after four weeks. You can also alternate between sites entirely, for example abdomen one week, thigh the next.

It is fine to inject into the same body region that you used for a different medicine, provided you choose a different spot within that region. If you are new to this type of treatment, our page on how the semaglutide injection works has additional context on how the medicine works once it reaches the tissue.

How do you actually administer the Wegovy injection step by step?

Once the site is clean and dry, pinch a fold of skin gently between thumb and forefinger. Place the pen flat against the skin, Wegovy pens are designed to inject at a 90-degree angle, so you do not need to tilt the pen. Press the pen firmly against the skin, then press the injection button.

Hold the pen in place and count slowly to six before lifting it away. This gives the full dose time to be delivered. You may hear a click when the injection starts and another when it is complete. A small red indicator in the pen window confirms the dose has been given.

Release the skin fold. You might see a tiny drop of blood or clear fluid at the site, this is normal. Press lightly with a clean piece of gauze or cotton if needed, but do not rub, as rubbing can affect absorption.

Dispose of the used pen immediately in a sharps container. Standard household bins are not appropriate for used injection pens; your local pharmacy can advise on collection points for full sharps containers. The detailed injection technique guide covers troubleshooting common issues such as the button feeling stiff or the pen not clicking.

What should you watch for after administering a semaglutide injection?

Mild redness or tenderness at the injection site is common and usually settles within a day. Rotating sites as described above reduces how often this happens. Gastrointestinal effects (nausea, some loose stools, or a feeling of fullness) are the most frequently reported side effects overall, and they tend to be most noticeable in the days following a dose increase rather than at a stable dose. Eating smaller meals and avoiding very fatty or rich food on injection day can help.

There are symptoms that need prompt medical attention. Severe stomach pain that spreads to the back, with or without vomiting, should be assessed urgently as it can indicate pancreatitis. This is an infrequent but recognised side effect of GLP-1 medicines; the MHRA highlighted it in a Drug Safety Update in January 2026. Signs of a serious allergic reaction (swelling around the face or throat, difficulty breathing, rapid heartbeat) also require emergency care.

You can report any suspected side effect directly to the MHRA via the Yellow Card scheme. Your prescriber should also know if side effects feel unmanageable, dose timing adjustments sometimes help, and that is a conversation worth having before stopping treatment.

If you have questions about whether semaglutide is right for you, our page covering semaglutide injections is a good starting point. For people thinking about starting treatment, checking your eligibility with our prescribers takes only a few minutes.